Brahim Afassy BrahimAfa

Nginx Performance Tuning: Understanding `ulimit`, File Descriptors, and Kernel Limits

A Step-by-Step Guide with Practical Examples

1. Introduction

Web servers like Nginx handle thousands of concurrent connections. To avoid bottlenecks, you must understand:

File Descriptors (FDs): How the kernel tracks open files/sockets.
Resource Limits (ulimit/rlimit): How the kernel enforces per-process limits.
Nginx Configuration: How to optimize settings like worker_rlimit_nofile and worker_connections.

source: http://www.skorks.com/2009/09/bash-shortcuts-for-maximum-productivity/

Command Editing Shortcuts

Ctrl + a – go to the start of the command line
Ctrl + e – go to the end of the command line
Ctrl + k – delete from cursor to the end of the command line
Ctrl + u – delete from cursor to the start of the command line
Ctrl + w – delete from cursor to start of word (i.e. delete backwards one word)
Ctrl + y – paste word or text that was cut using one of the deletion shortcuts (such as the one above) after the cursor

Git Submodules basic explanation

Why submodules?

In Git you can add a submodule to a repository. This is basically a repository embedded in your main repository. This can be very useful. A couple of advantages of using submodules:

You can separate the code into different repositories.

Github deployment

Requirements:

DigitalOcean Droplet (Ubuntu 20.04+) should be created
Github repository

Prepare DO Droplet Server:

ssh root@DROPLET_IP
sudo vi /etc/ssh/sshd_config
change PasswordAuthentication from no to yes

Ngrok

Overview

ngrok allows you to expose a web server running on your local machine to the internet.

Read more about ngrok in the official docs.

Installation

Reset root password on scaleway.com

Source: https://community.online.net/t/reset-root-password-via-console/1724/3

I solved this problem, found a hint here: https://github.com/scaleway/initrd/tree/master/Linux 184.

Here is what I did:

Edit the “Tags” field in the server definition and add “INITRD_POST_SHELL=1” as one (or the only) tag.

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

Secured HLS setup with Nginx as media server

This example is part of this article.

This is an example for an HLS delivery with basic security. Nginx compiled with nginx-rtmp-module & secure-link is used as media server. Features:

Domain filtering
Referrer filtering
Embed buster

	[supervisord]
	nodaemon=true
	loglevel=debug

	[program:amon]
	command=gunicorn -c gunicorn.conf.py wsgi
	directory=/amon
	autostart=true
	autorestart=true
	redirect_stderr=true

	# Sample Nginx config with sane caching settings for modern web development
	#
	# Motivation:
	# Modern web development often happens with developer tools open, e. g. the Chrome Dev Tools.
	# These tools automatically deactivate all sorts of caching for you, so you always have a fresh
	# and juicy version of your assets available.
	# At some point, however, you want to show your work to testers, your boss or your client.
	# After you implemented and deployed their feedback, they reload the testing page – and report
	# the exact same issues as before! What happened? Of course, they did not have developer tools
	# open, and of course, they did not empty their caches before navigating to your site.